How To Break Up String Of Key Value Pairs

I have a variable that reads in a POST from paypal. This is the instant payment notification stream and all the keys and values are stored into a string variable .

mc_gross=0.05&protection_eligibility=Ineligible&payer_id=UEWAFF732VL&tax=0.00&payment_date=22%3A36%3A55+Jul+21%2C+2009+PDT&payment_status=Completed&charset=windows-1252&first_name=Scot

This is part of the string. How do I break this up into a set of variables. I tried using request.form but this did not do anything. I'm trying to get the variables and then pass them to a function that will write everything to a database.

Dim amount = Request.Form("mc_gross")
Dim currency = Request.Form("currency")
Dim pmtdate = Request.Form("payment_date")
Dim status = Request.Form("payment_status")

I only need certain variables from this variable which is strNewvalue. How to I get the values stored in this variable?

Response.Write(IPNResponse)
Dim myEmail As MailMessage = New MailMessage()
myEmail.To = "e@aol.com"

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